Data transmission is performed on a Physical Uplink Shared Channel(PUSCH). In order to be able to schedule the PUSCH, a base station (eNodeB) receives a Sounding Reference Signal (SRS) transmitted from a user equipment(UE). The SRS is used by the eNodeB, e.g. to estimate the uplink channel quality. The uplink channel quality is further used for determining the resource block (RB) allocation and for determining the applied modulation and coding scheme of the PUSCH transmission.
However, in LTE Rel-10 system, the SRS transmission scheme is designed based on the presence of a Physical Uplink Control Channel (PUCCH). In a case that the PUCCH is removed for a non-backwards compatible Uplink Secondary Component Carrier (UL SCC), proper and efficient scheduling decisions are difficult to make, since the SRS transmission has been optimized for a backwards compatible UL SCC having a different configuration. Due to these difficulties, a non-optimal scheduling happens, which does not make use of all available resources in the system.